Dispersion liquid, composition, sealing member, light-emitting device, llumination tool, display device, method for producing dispersion solution, and method for modifying surfaces of metal oxide particles

Abstract

In a dispersion liquid according to the present invention, regarding metal oxide particles that are obtained by vacuum-drying a dispersion liquid containing the metal oxide particles which have been surface-modified by at least one kind of a silane compound containing a methyl group and a hydrocarbon group having 2 or more carbon atoms and at least one kind of silicone compound, in a case where a transmission spectrum in a wavenumber range of 800 cm -1 or higher and 3,800 cm -1 or lower is measured by FT-IR, and values of the transmission spectrum are standardized, the following expression (1) is satisfied. IA/IB ≤ 3.5 (1) (“IA” represents a spectrum value standardized at 3,500 cm -1 , and “IB” represents a spectrum value standardized at 1,100 cm -1 ).

1 . A dispersion liquid comprising:
 metal oxide particles which have been surface-modified by at least one kind of silane compound and at least one kind of silicone compound; and   a solvent,   wherein the silane compound contains a methyl group and a hydrocarbon group having 2 or more carbon atoms,   a mole ratio (methyl group/hydrocarbon group) of the methyl group to the hydrocarbon group in the metal oxide particles is 0.01 or more and 10 or less,   in a case where a transmission spectrum of the metal oxide particles that are obtained by drying the dispersion liquid by vacuum drying is measured in a wavenumber range of 800 cm -1  or higher and 3,800 cm -1  or lower with a Fourier transform infrared spectrophotometer, and values of the transmission spectrum are standardized such that a maximum value of the transmission spectrum in the range is 100 and a minimum value is 0, the following expression (1) is satisfied,
                   IA     /     IB       ≤   3.5           ­­­(1)               
   (in the expression, “IA” represents a spectrum value standardized at 3,500 cm -1 , and “IB” represents a spectrum value standardized at 1,100 cm -1 ).   
     
     
         2 . The dispersion liquid according to  claim 1 ,
 wherein the hydrocarbon group having 2 or more carbon atoms is an aromatic hydrocarbon group.   
     
     
         3 . A composition, which is a mixture of the dispersion liquid according to  claim 1  and a silicone resin component. 
     
     
         4 . A sealing member, which is a cured product of the composition according to  claim 3 . 
     
     
         5 . A light-emitting device, comprising:
 the sealing member according to  claim 4 ; and   a light-emitting element sealed with the sealing member.   
     
     
         6 . An illumination tool, comprising:
 the light-emitting device according to  claim 5 .   
     
     
         7 . A display device, comprising:
 the light-emitting device according to  claim 5 .   
     
     
         8 . A method for producing the dispersion liquid according to  claim 1 , comprising:
 a step of mixing a first surface-modifying material and metal oxide particles to obtaining a liquid mixture;   a step of dispersing the metal oxide particles in the liquid mixture; and   a step of adding a second surface-modifying material to the liquid mixture to obtain a dispersion liquid,   wherein a content of the metal oxide particles in the liquid mixture is 10% by mass or more and 49% by mass or less,   a total content of the first surface-modifying material and the metal oxide particles in the liquid mixture is 65% by mass or more and 98% by mass or less,   the first surface-modifying material is a silane compound containing a methyl group, and   the second surface-modifying material contains a silane compound containing a hydrocarbon group having 2 or more carbon atoms and a silicone compound.   
     
     
         9 . A method for modifying surfaces of metal oxide particles, comprising:
 a step of mixing a first surface-modifying material and metal oxide particles to obtain a liquid mixture;   a step of dispersing the metal oxide particles in the liquid mixture; and   a step of adding a second surface-modifying material to the liquid mixture,   wherein a content of the metal oxide particles in the liquid mixture is 10% by mass or more and 49% by mass or less,   a total content of the first surface-modifying material and the metal oxide particles in the liquid mixture is 65% by mass or more and 98% by mass or less,   the first surface-modifying material is a silane compound containing a methyl group, and   the second surface-modifying material contains a silane compound containing a hydrocarbon group having 2 or more carbon atoms and a silicone compound.   
     
     
         10 . The dispersion liquid according to  claim 1 ,
 wherein the metal oxide particles which have been surface-modified by the at least one kind of silane compound and the at least one kind of silicone compound are secondarily modified metal oxide particles obtained by   primarily modifying metal oxide particles by a first surface-modifying material composed of a silane compound containing a methyl group and not containing a hydrocarbon group having 2 or more carbon atoms, and   secondarily modifying the primarily-modified metal oxide particles by   a second surface-modifying material composed of one or both of a second silane compound containing a methyl group and a hydrocarbon group having 2 or more carbon atoms and a second silane compound not containing a methyl group and containing a hydrocarbon group having 2 or more carbon atoms and a silicone compound.   
     
     
         11 . The dispersion liquid according to  claim 1 ,
 wherein the metal oxide particles are zirconium oxide particles or titanium oxide particles.   
     
     
         12 . The method for producing a dispersion liquid according to  claim 8 , further comprising:
 a step of hydrolyzing the first silane compound before being mixed with the metal oxide particles; and   a step of hydrolyzing the second silane compound before being added to the liquid mixture,   wherein the dispersion step is carried out using a disperser.   
     
     
         13 . The method for producing a dispersion liquid according to  claim 12 , further comprising one or both of, between the dispersion step and the step of obtaining the dispersion liquid:
 a step of adding a hydrophobic solvent to the dispersed liquid mixture; and   a step of removing an alcohol generated in the hydrolyzing step.   
     
     
         14 . The method for modifying surfaces of metal oxide particles according to  claim 9 , further comprising:
 a step of hydrolyzing the first silane compound before being mixed with the metal oxide particles; and   a step of hydrolyzing the second silane compound before being added to the liquid mixture;   wherein the dispersion step is carried out using a disperser.   
     
     
         15 . The method for modifying surfaces of metal oxide particles according to  claim 14 , further comprising one or both of, between the dispersion step and the step of obtaining the dispersion liquid:
 a step of adding a hydrophobic solvent to the dispersed liquid mixture; and   a step of removing an alcohol generated in the hydrolyzing step.   
     
     
         16 . The method for producing a dispersion liquid according to  claim 8 ,
 wherein the silane compound containing a methyl group does not contain a hydrocarbon group having 2 or more carbon atoms.   
     
     
         17 . The method for modifying surfaces of metal oxide particles according to  claim 9 ,
 wherein the silane compound containing a methyl group does not contain a hydrocarbon group having 2 or more carbon atoms.